All that is because they first believed and then disbelieved, and therefore a seal was set on their hearts; as a result they understand nothing.
यह इस कारण कि वे ईमान लाए, फिर इनकार किया, अतः उनके दिलों पर मुहर लगा दी गई, अब वे कुछ नहीं समझते